1. Field of Invention
The present invention relates to a vacuum cleaner, and more particularly, to a vacuum cleaner having an improved inner filter structure for a dust collecting unit thereof.
2. Description of the Prior Art
A vacuum cleaner is an apparatus which sucks air containing foreign materials using a vacuum pressure generated by a vacuum motor installed in a main body of the vacuum cleaner, filters out foreign materials such as the dust and dirt in the main body, and then collects and discharges the dust and dirt.
A cyclonic vacuum cleaner which has recently been widely used is designed to filter out dust and dirt in such a manner that relatively heavy dust and dirt are moved outward by a centrifugal force in air flow swirling at a high speed and collected in a specific dust collecting chamber, whereas fine dust and dirt which are not filtered out by the cyclonic method are filtered by a filter such as a pleated filter.
FIG. 1 shows a vacuum cleaner for performing a general cyclonic filtering process.
Referring to FIG. 1, the vacuum cleaner comprises a main body 10 in which a suction means for sucking air in a room is installed, a flexible connection tube 24 which is connected to the main body 10 to communicate with the interior of the main body, a variable length extension tube 22 which is connected to an end of the connection tube 24 to communicate with the interior of the connection tube, and a suction nozzle 21 for sucking the air containing foreign materials from a floor by means of a suction force generated in the main body 10.
Further, in the main body 10 is installed a dust collecting unit 11 which is detachably mounted to a rear side of the main body. The dust collecting unit 11 causes the air sucked from the suction nozzle 21 to be introduced therein and then the dust and dirt in the air to be collected in a cyclonic fashion. Further, at one side of the main body 10 is formed a discharge portion 19 for discharging the air, from which the foreign materials are filtered out through the dust collecting unit 11, to the atmosphere.
A pair of wheels 18 for traveling the main body 10 on the floor are rotatably installed on a lower surface of the main body 10. Further, a power cord 16 for supplying the vacuum cleaner with electric power is installed at another side of the main body 10. The power cord 16 can be wound around a cord reel (not shown) in the main body and stored in the main body.
The dust collecting unit 11 includes a grip 12 for allowing a user to hold the unit when it is rearward mounted to or demounted from the main body 10. Further, a handle 14, which the user can grip when intending to carry the vacuum cleaner, is installed at a top surface of the main body 10.
In the dust collecting unit 11, an additional fine filter (not shown) can be mounted as a secondary dust collecting means for filtering out fine dust and dirt which remain after a primary cyclonic dust collecting process has been performed. As the vacuum cleaner is repeatedly used for a long time, fine dust and dirt are continuously accumulated in the, fine filter. Therefore, there is inconvenience in that the accumulated dust and dirt should be repeatedly cleaned.
Further, there is a problem in that if the fine dust and dirt are continuously accumulated in the fine filter, the filter should be frequently replaced with a new one.